JP4571924B2 - Yeast extract and method for producing the same - Google Patents

Description

  The present invention relates to a yeast extract containing a high content of 5'-nucleotides, in particular, containing 5% by weight or more of 5'-guanylate, and a method for producing the same.

Yeast extract has a strong taste and is blended with other seasonings, and is widely used for food materials, seasonings and the like. Taste components of yeast extract are amino acids, peptides, saccharides, 5′-nucleotides, etc., among which 5′-nucleotides, especially 5′-sodium guanylate (hereinafter also simply referred to as GMP) and 5 ′. -Sodium inosinate (hereinafter also simply referred to as IMP) is important as a umami component and a rich taste component. Thus, a method for containing a large amount of these natural 5′-nucleotides in a yeast extract has been developed, and a report (Patent Document 1) on a method of extracting RNA from a yeast cell after heat treatment, causing phosphodiesterase to act, and the like has been published. Has been made.
Yeast extracts containing these 5'-nucleotides have a unique taste and richness, but are disadvantageous in that orientation tends to occur when a high concentration solution is used or when blended with other food materials and seasonings. was there.

In general, as a method for obtaining a yeast extract that is clear or becomes turbid when dissolved in water, heated, or the like and free of soil, for example, the following method (Patent Document 2) is known. (1) A method in which the yeast extract stock solution is kept at a low temperature for a long time and then the precipitate is filtered off. (2) A method in which chitosan and polyacrylate are added to the yeast extract aqueous solution to remove water-insoluble matter, (3 ) Heating the yeast extract, filtering off the resulting solids and adsorbing the colored substances to the ion exchange resin, (4) Removing the insoluble matter deposited with the yeast extract having a pH of 6.1 or higher .
However, when these methods are applied to a yeast extract containing a 5′-nucleotide, there is a drawback that the unique taste and richness are reduced.

Therefore, a method that can be applied to a yeast extract containing 5′-nucleotide has been studied. For example, in Patent Document 3, the yeast extract is heated at 70 to 95 ° C. without separating the yeast cells, and then the pH is adjusted. A method for removing the turbid components that have been prepared to 4.0 to 6.0 and removing the precipitated turbid component is disclosed in Patent Document 4, in which the yeast extract is microfiltered with a ceramic membrane, and then the solid concentration is 10 to 50% by weight. The method of concentrating to 1 and adding activated carbon and filtering is disclosed, respectively.
However, these methods mainly remove the heat-precipitated protein or coloring substance in the yeast extract, and although the 5'-nucleotide content is low, for example, about several percent of the yeast extract is improved, further 5 ' -It was difficult to say that the occurrence of orientation in a high-concentration solution of yeast extract containing a high amount of nucleotides was sufficient.
WO88 / 05267 and JP-A-6-113789 Japanese Patent Laid-Open Nos. 7-51024, 8-56611, WO 98/46089, 2002-306120 Japanese Patent Laid-Open No. 11-187842 JP 2004-248529 A

  The present invention provides a yeast extract containing 5% by weight or more of 5′-nucleotides, particularly 5′-GMP, and a method for producing the same, with little occurrence of orientation even when the yeast extract is made into a high concentration solution. This is the issue.

The present inventors have found that a polyamine contained in a yeast extract reacts with GMP to produce oli, and by removing such polyamines, a yeast extract with almost no oli production is obtained. The present invention has been reached.
That is, the present invention
(1) A yeast extract having a GMP content of 5% by weight or more and a polyamine content of 0.02% by weight or less,
(2) The yeast extract according to (1) above, wherein the yeast extract further contains 5% by weight or more of IMP,
(3) The yeast extract according to (1) or (2) above, wherein the yeast is a genus Candida.
(4) The yeast extract according to any one of (1) to (3), wherein the polyamine is spermine,
(5) A 5'-sodium guanylate content containing 5% by weight is characterized by treating a yeast extract solution containing 5'-sodium guanylate with a weakly acidic cation exchange resin or an adsorption resin. The method for producing a yeast extract having a polyamine content of 0.02% by weight or less,
(6) A 5'-sodium guanylate content is 5% by weight or more, characterized in that a phosphodiesterase is allowed to act after treating a yeast extract containing RNA with a weakly acidic cation exchange resin or an adsorption resin. , A method for producing a yeast extract having a polyamine content of 0.02% by weight or less,
Is to provide.

  Although the yeast extract of the present invention is a yeast extract containing 5% by weight or more of GMP, preferably further IMP, there is almost no occurrence of orientation even when dissolved at a high concentration. Have

Hereinafter, the present invention will be described in detail.
The yeast extract of the present invention contains GMP in an amount of 5% by weight or more, preferably 7% by weight or more, more preferably 10% by weight or more.
When the content of GMP is less than 5% by weight, it is inferior to the special taste and richness, and when used for food materials, seasonings, etc., it is not preferred because it is limited by the blending amount.
In the present invention, it is preferable that the yeast extract further contains IMP almost the same as GMP.

The yeast extract of the present invention has a polyamine content of 0.02% by weight or less, preferably 0.015% by weight or less, more preferably 0.01% by weight or less.
Polyamines usually refer to polyamines contained in yeast cells, such as putrescine, spermidine, spermine, etc. Among them, spermine is particularly likely to react with GMP to form a precipitate.
When the content of polyamines exceeds 0.02% by weight, when dissolved at a high concentration, for example, when a solution in which a yeast extract is dissolved is incubated at 5 ° C. for 24 hours, it is not preferable. The occurrence of orientation varies depending on the concentration, storage conditions, and the like. Needless to say, even if the yeast extract of the present invention is dissolved at a higher concentration, the orientation is hardly generated under conditions such as room temperature.

  Examples of the yeast used in the present invention include yeasts of the genus Saccharomyces, Hansenula, and Candida, which are edible yeasts. preferable.

The yeast extract of the present invention can be produced by dissolving a yeast extract containing 5% by weight or more of GMP and then removing the polyamines. Further, a method for producing a known yeast extract containing 5% by weight or more of GMP is used. In the process, it is more advantageously produced by incorporating a process for removing polyamines.
That is, RNA and extract were extracted from yeast cells by protease treatment, heat extraction, alkaline extraction, etc., and then 5′-phosphodiesterase, 5′-adenylate deaminase, etc. were allowed to act to contain GMP (and IMP). In a method of concentrating and drying a yeast extract, the polyamines are removed using an RNA and extract extract (RNA-containing yeast extract), or a yeast extract containing GMP and the like after the enzymatic reaction Containing 5MP-phosphodiesterase, protease, 5'-adenylate deaminase directly on yeast cells by removing polyamines using the product, and then removing the cells and containing GMP (and IMP) This yeast extract can be used as it is or after concentration, after removing polyamines, and concentrated and dried. Can be manufactured.
Known conditions can be used for extraction conditions such as RNA and extract from yeast cells, enzyme reaction conditions, and the like.

Any method can be used to remove the polyamines. In particular, a method of treating with a weakly acidic cation exchange resin or an adsorbent resin is preferable because the polyamines can be removed without losing the umami component and the kokumi component.
The treatment conditions of the weakly acidic cation exchange resin or the adsorption resin are not particularly limited as long as they are capable of adsorbing polyamines, and well-known conditions are applicable. Or when using the melt | dissolution of the yeast extract containing polyamines, it is preferable that a liquid transmission rate (SV) is about 0.5-5, and a process liquid is about 10 times or less of resin volume.
As the weakly acidic cation exchange resin that can be used, acrylic resins are preferable. For example, Amberlite IRC-76 (manufactured by Organo Corporation), Diaion WK10, 20 (manufactured by Mitsubishi Chemical Corporation), Lebatit CNP -80, CNP-C (manufactured by Bayer Co., Ltd.) and the like.
The adsorbent resin is preferably an aromatic resin or an aromatic modified resin. For example, Diaion HP20, 21, Sepabead SP207, 825, 850 (Mitsubishi Chemical Corporation), Amberlite XAD2 , 4 and 7 (manufactured by Organo Corporation), and the like.
Among these resins, when using weakly acidic cation exchange resins, if the treatment is performed while keeping the pH of the treatment solution constant, the polyamine removal rate is high and the extract can be recovered sufficiently even if the amount of resin used is small. preferable.

  The solution from which the polyamines have been removed is concentrated as necessary and dried by spray drying or the like, thereby containing 5% by weight or more of GMP, and the content of the polyamines is 0.02% by weight or less. Yeast extract.

A feature of the present invention is that polyamines are removed from a yeast extract containing a high amount of GMP.
Normally, polyamines are contained in yeast cells in a large amount of about 0.1 to 0.2% by weight, and polyamines are also extracted and extracted effectively when RNA, extract, etc. are extracted. It was contained in the yeast extract. The present inventors have found that such polyamines react with GMP and precipitate from the solution. Therefore, if the polyamines are removed, the yeast extract can be dissolved at a high concentration even if the GMP content is high. In addition, it was found that no ori were formed, and the clarification of the conventional yeast extract or the removal of turbidity and ori-producing substances focused on removing proteins or colored substances. On the other hand, the present invention has been completed from a new viewpoint different from these.

Hereinafter, the present invention will be described more specifically with reference to examples.
In addition, content of the polyamine shown to the present Example was measured according to the method of Kawakami et al. (The Journal of the Japan Society for Pediatric Nutrition and Gastroenterology, Vol. 9, p. 115, 1995). Ori was visually observed after incubating the solution at 5 ° C. for 24 hours.

Test example 1
5′-sodium guanylate was dissolved in sterilized water, and then the pH was adjusted to 5.8 to prepare a GMP 1 wt% solution (a model of a 20 wt% solution of yeast extract containing 5 wt% GMP). To 10 ml of this solution, 10 ml of putrescine solution, spermidine solution or spermine solution of each concentration separately prepared was added and incubated at 5 ° C. for 24 hours.
The results are shown in Table 1.
Table 1 shows that GMP reacts with polyamine to produce oli, that spermine tends to generate oli at the lowest molar concentration, and the amount of polyamine is about 0.004% by weight or less (yeast extract containing 5% by weight of GMP). If converted, 0.02% by weight or less of the yeast extract), it can be seen that almost no orientation occurs regardless of the type of polyamine.

Example 1
As a yeast extract containing 5% by weight or more of GMP, “Alomild” manufactured by Kojin (GMP content 10.9% by weight, IMP content 10.9% by weight, polyamines content 0.27% by weight) was used. 60 ml of a 5 wt% aqueous solution was prepared. This was passed through a column containing 30 ml of weakly acidic cation exchange resin (Amberlite CG-50), then washed with 60 ml of distilled water, and combined to obtain a polyamine removing solution.
The polyamine-removed solution was concentrated to 61 ml and incubated at 5 ° C. for 24 hours. However, the solution was clear and no occurrence of orientation was observed.
In addition, the recovery rate of GMP and IMP in the resin treatment is 98% (UV absorption), and the content of polyamines in the polyamine removal solution is 0.008% by weight with respect to the polyamine removal solution concentrated dry solid (yeast extract). %Met.
Further, in the alomilized 5% by weight solution before the resin treatment, the occurrence of orientation (white turbidity) was observed under the same conditions.

Example 2
Using “Alo-Mild” manufactured by Kojin Co., Ltd. used in Example 1, 60 ml of a 5 wt% aqueous solution thereof was prepared. To this, 15 ml of weakly acidic cation exchange resin (Diaion WK-11) was added, 10N-NaOH solution was added little by little, and ion exchange treatment was performed while adjusting the pH to 5.6 (final NaOH). The amount added was 0.58 ml.)
Next, the ion exchange resin was removed by filtration, and the resin was washed with distilled water, and the filtrate and the washing solution were combined and concentrated to 61 ml, and then incubated at 5 ° C. for 24 hours. I couldn't.
The recovery rate of GMP and IMP in the resin treatment is 98% (UV absorption), and the content of polyamines in the polyamine removal solution is 0.003 wt.% With respect to the polyamine removal solution concentrated dry solid (yeast extract). %Met.

Example 3
Using “Alomild” manufactured by Kojin Co., Ltd. used in Example 1, 1 L of a 5 wt% aqueous solution thereof was prepared. This was passed through a column containing 150 ml of an adsorption resin (SP-825) at SV = 5, then washed with distilled water, and combined to obtain a polyamine removing solution.
The polyamine-removed solution was concentrated to 1 L and then incubated at 5 ° C. for 24 hours. However, the solution was clear and no occurrence of orientation was observed.
The recovery rate of GMP and IMP in the resin treatment is 95% (UV absorption), and the content of polyamines in the polyamine removal solution is 0.0149 weight with respect to the polyamine removal solution concentrated dry solid (yeast extract). %Met.

Example 4
1000 ml of 10% cell suspension of Candida utilis CS7529 strain was heated at 90 ° C. for 30 minutes to completely inactivate intracellular enzymes, then cooled to 40 ° C., and Protin PC-10 (Daiwa Kasei Protease) Formulation) 0.5 g was added and stirred at 40 ° C. for 10 hours. Next, the enzyme is heated to inactivate, 0.1 g of ribonuclease Amano D (manufactured by Amano Pharmaceutical) is added at 65 ° C. and reacted for 5 hours, and 0.1 g of deamizyme (manufactured by Amano Pharmaceutical) is further added at 50 ° C. The mixture was reacted for 5 hours, insoluble solids were removed by centrifugation, and the mixture was heated at 90 ° C. for 35 minutes to obtain a yeast extract.
Half of the yeast extract is passed through a column containing 150 ml of weakly acidic cation exchange resin (Amberlite CG-50), washed with 300 ml of distilled water, combined with the passing solution, concentrated, spray-dried, 12.9 g of the yeast extract of the invention was obtained.
The GMP content in the yeast extract was 10.8%, the IMP content was 11.2% by weight, and the polyamine content was 0.0124% by weight.
An aqueous solution of 5% by weight of the yeast extract was prepared and incubated at 5 ° C. for 24 hours, but the solution was transparent and no occurrence of orientation was observed.
Yeast extract obtained by concentrating and spray-drying the remaining half without resin treatment (GMP content 10.5% by weight, IMP content 11.0% by weight, polyamine content 0.3% by weight [putrescine 0.069, spermidine 0.170, spermine was 0.065% by weight]), and a significant amount of oliage (white turbidity) was generated under the same conditions.

  Although the yeast extract provided by the present invention contains 5% by weight or more of GMP, even if it dissolves and is blended at a high concentration, there is almost no occurrence of sediment, so it is limited to the food and blending amount used. It can be widely used as a food material, seasoning and the like.

Claims (6)

  A yeast extract having a 5'-sodium guanylate content of 5 wt% or more and a polyamine content of 0.02 wt% or less.   The yeast extract according to claim 1, wherein the yeast extract further contains 5% by weight or more of sodium 5'-inosinate.   The yeast extract according to claim 1 or 2, wherein the yeast is a Candida genus yeast.   The yeast extract according to any one of claims 1 to 3, wherein the polyamine is spermine.   A solution of yeast extract containing 5′-sodium guanylate is treated with a weakly acidic cation exchange resin or an adsorption resin, and the content of sodium 5′-guanylate is 5% by weight or more, polyamine A method for producing yeast extract having a content of 0.02% by weight or less.   The 5'-sodium guanylate content is 5% by weight or more, characterized in that the phosphodiesterase is allowed to act after treating the yeast extract containing RNA with a weakly acidic cation exchange resin or an adsorption resin. The manufacturing method of the yeast extract whose content is 0.02 weight% or less.